Besides being the Greek Goddess of Wisdom, Athena has done many things that would make her one of the greatest Gods of Olympus (with accounting for Zeus). First of all, Athena was the Patron of Athens, and bestowed the gift of the olive tree to the Athenians. This was decided as Poseidon (king of the ocean) was competing against Athena for the title of Patron, and the Athenians demanded a gift from the God/Goddess if they were chosen. Poseidon would give them a salt water spring (which was undrinkable), but Athena would give the Athenians the olive tree, and so they chose just that. This is important because the olive tree provided food, shade and wood to the people of Athens. Moreover, Athena assisted many heroes on their journeys, such as
